Long-stroke pumping mechanism



A ril 6,1926. 1,579,908

I M. T. ARCHER ET AL LONG STROKE PUMPING MECHANISM Filed April 15, 19252 Sheets-Sheet 1 W INVENTORS ATTORNEY A ril 6, 1926. 1,579,908

M. T. ARCHER ET AL LONG STROKE PUMPING MECHANISM Filed April 15, 1925 2Sheets-$fieet 2 I INVENTORS.

WLfi W1) A TTORNEY' Patented Apr. 6, 1926.

UNITED STATES AT NY orrics. v

MER'ION T. ARCHER, OF PITTSBURGH, PENNSYLVANIA, AND JOSEPH IYIAHAH, OFTOLEDO, OHIO, ASSIGNORS TO THE NATIONAL SUPPLY COMPANY, OF TOLEDO, OHIO,

1 CORPORATION OF OHIO.

LONG-STROKE PUME'ING MECHANISM.

Application filed. April 13, 1825. Serial No. 22,588.

To all whom it may concern: I

Be it kno vn that we, MEI-tron T. linonnn, a citizen of the UnitedStates, residing at Pittsburgh, in the county of Allegheny and State ofPennsylvania, and Josr; H R. MAI-IAN, a citizen of the United States,residing at Toledo, in the county ofLucas and State of Ohio, haveinvented new and useful Improvements in Long-Stroke Pump,

ing Mechanism, of which the following is a,

specification.

Our invention relates to long-stroke pumping mechanisms. The objects ofthe invention are to provide a pair of intermeshing elliptical planetarygears having novel means for fixing the distance between their centerswithout the use of shrouds; and to provide special means to preventrelativetransverse or lateral motion of the gears. Other objects appearhereinafter.

Referring'to the accompanying drawings, Fig. 1' is a side view of aportion of a pumping mechanism employing our invention; Fig. 2, acentral transverse section through the two centers on which the gearsturn, the section being taken on the line II-II of Fig. 3; and Fig. 3, asection on the line III-III of Fig. 2.

1 designates the floor of a derrick and 2 is a post on whose upper endthe walking beam 3 oscillates. The right-hand end of.

the walking beam may operate a pump or other device. old and well known.

The left-hand end of the walking beam 3 has suspended therefrom the pitman at which is secured between thetwo lugs 5 projecting horizontallyfrom one face of the traveling'or planet gear .6. This gear 6 mesheswith the gear '7 keyed to the drive shaft 8 deriving its rotary motionfrom any suitable prime mover. The shaft 8 is supported at the endshown, by the post 9.

The gears 6 and 7 are substantially elliptical. The gear 6 is composedof two spaced peripherally-toothed elliptical members 10 and 11connected together by the central hub 12; and the gear 7 is composed oftwo spaced peripherally-toothed members 18 and 14 connected together bythe central hub 15, the members 10 and 11 meshing re spectively with themembers 13 and 14. The shaft 8 is keyed to the hub 15 and the shimsseated between the members 13 and 1% at The parts described are alladjacent portions of the members 13 and 14K. Thegears turn on centerswhich are at the intersection of their major and minor has two openingsto receive the rollers 19 and '20 rotatable on the pin21 extendinglengthwise through the frame in line with the centers of the hubs 12 and15. The rollers approxi ately it betwcen'the members ofthe gears.

22 is a cap seated between the members 10 and 11 and at tne outer sideof the hub 12. Its ends at each side of the hub are spaced from the endof the frame by the 24 is a cap like cap It is the outer side of the hub15. Its ends at each side of the hub are spaced from the end of theframe by, the shims 25. Two bolts 26 extenthat opposite sides of thehubs, entirely through both caps and the frame 18, and are provided withnuts 27 which screw tightly against the caps to secure the describedpartsin a unitary str cture. The parts are so made that, when the shimsare tightly clamped between the caps and the frame 18, the hubs are wellsupported on all sides. Some of the shims may be re- I moved from timeto time as the parts wear.

Then the nuts will be tightened compensatively.

l l hile the gear 7 is making two complete rotations the gear 6 makesone complete revolution. Assuming that the gear 7 ro tates as indicatedby the a'row, the minor axis of the gear 6 will be in alinement with themajor axis of the gear 7, when the major axis becomes horizontal, andthe major axis of the gear 6 will be in alinementwith the minor axis ofthe gear 7 when the latter axis is vertical. Accordingly, the stroke ofthe pitman at is the sum of the major and minor axes of the gears.

against the op- Fig. 3 shows the positions of the gears major axis ofthe gear 7 and the minor axis ofthe gear 6 are first in a horizontalline. When the gear 7 has been rotated a half revolution further, themajor axis of gear 6 and the minor axis of the gear 7 will be in avertical line. At the conclusion of another half revolution of the gear7 the major axis of the gear 7 and the minor axis of the gear 6 willagain be in a horizontal line. When the gear 7 has moved another halfrevolution, the major axis of the gear 6 and the minor axis of the gear7 will be again in a vertical line.

During the operation of the walking beam 3 by the gears (3 and 7, thereare two periods in the travel of the gears 6 completely around the gear7 when the walking beam is at rest, these periods being when the gear 6is directly over the gear 7, and when it is directly under the same. Atthese two periods the up-stroke and the down-stroke of the right-handend of the walking beam are about to begin. If a pump is attached to therighthand end of the walking beam, the strokes of the pump would beginas the walking beam and pitman start from rest, and the strokes wouldaccelerate according to a modified sine curve to a maximum speed, atwhich time the major axis of the gear 7 becomes approximatelyhorizontal.From this time the strokes decelerate until the gear 7 is againhorizontal and the gear 6 is directly above or below the gear 7, atwhich place the walking beam has a period of rest, the gear 7 havingthen made a complete rotation. Further movement of the gear 7 for thenext complete revolution, causes the cycle just described to berepeated, except that the direction of travel of the pitman and the endsof the walking beam would be reversed. The described acceleration anddeceleration of the strokes from periods of rest are very advantageousfor the operation of the reciprocating pumps, because the impact due tothe reversal of the direction of travel of the moving parts is decidedlydampened, and be cause the speed of travel of the moving partsaccelerates from zero gradually to a maximum and then deceleratesgradually to Zero. The elliptical gears cushion the impacts set up atthe changes of direction of strokes.

Not only does the frame 18 ii): the distance between the centers ofrotation of the gears, and thereby n'event any tendency toward thecrushing of the gear teeth, but the frame prevents any appreciablerelative lateral mo tion of the gears. The pitman being on one face ofthe gear (5 causes thrusts to be exerted tending to overturn the gears.This leverage is much shortened by the employment of the rollers 19 and20. If the gear 6 has a tendency to move downwardly in Fig. 2 owing tothe action of a pitman secured between the lugs 5, the frame 18 would beurget downwardly, the gear 6 acting at the point 28 on the roller 19,which causes pressure of the roller 20 against the point 29 on the gear7. Not only is the gear 6 prevented thereby from appreciable movementlateral on the gear 7, but the leverage lending to overturn the gearshas only the distance from the center of the shaft 8 to the point 29. Incase the pitman tends to push the gear 6 upwardly in Fig. 2, the gear (3will engage the roler l9 opposite the point SS, and the roller 20 will,at a place opposite the point push against the gear 7.

We claim:-

1. A shaft, a pitman, and a. pair of plane tary gears fixed to the shaftand pitman respectively, each. gear comprising two parallel membersconnected by a hub, in combination with a frame situated between themembers of each gear and spacing the centers of the gears apart, andmeans carried by the frame for linking the gears together.

A. shaft, a pitman, and a pair of planetary gears fixed to the shaft andpitnran respectively, each gear comprising two parallel membersconnected by a hub, in combination with a frame situated between themembers of each gear and spacing the centers of the 621 rs apart, meanscarried by the frame for linking the gears together, and rollers carriedby the fame and arranged to contact with the opposing faces of the saidgear members.

3' A shaft, a pitman, and a pair of plan etary gears fixed to the shaftand pitlnan respectively, each gear comprising two para lel membersconnected by a hub, in combination with a frame situated between themembers of each gear, means carried by the frame for linking the gearstogether, and rollers carried by the frame and arranged to contact withthe opposing faces of the said gear members.

The combination of a shaft, a pitman, a pair of intergeared ellipticalgears, one keyed to the shaft and the other secured to the pitman, andmeans: linking the gears together, the gears being arranged so that theminor axis of the driving gear is substantial y in line with the pitmanwhen the pit man is about to change the direction of its stroke.

In testimony whereof we hereunto atlix our si natures this (5th day ofApril, 19:25.

MERTON T. ARCH ER JOSEPH R. MAHAN.

